Microsoft SQL Service Accounts

It is generally not a good practice to give service accounts DBO rights, unless absolutely necessary. Service accounts often interact with external systems and having such high privileges can pose a significant security risk if the account is compromised. Here are some best practices and recommendations:

  1. Principle of Least Privilege (PoLP): Assign the minimum permissions necessary for the service account to perform its tasks. If DBO rights are not required, don’t assign them.
  2. Separate Roles: Use different accounts for different roles and tasks. The service account for application interactions should be separate from the one performing administrative tasks like backups, for instance.
  3. Periodic Review: Regularly review the permissions of your service accounts. If a service account no longer needs certain permissions, they should be revoked.
  4. Avoid Hard-Coded Credentials: Never hard-code service account credentials into your application code. If your code is exposed, so are your credentials.
  5. Use Encryption: Always encrypt connections to your database using SSL/TLS.
  6. Monitor and Audit: Continually monitor service accounts for any suspicious activity, and have an audit log for traceability.
  7. Password Rotation and Complexity: Implement policies for strong, complex passwords and regular password rotation.
  8. Consider Managed Identity: If you are using cloud providers like Azure or AWS, you can consider using managed identities (in Azure) or IAM roles (in AWS). They provide an identity for your application to use without needing credentials in your code.

By adhering to these best practices, you can maintain a secure database environment while still allowing your services and applications the access they need.

 

WINDOWS AD CONFIGURATION

In Microsoft Active Directory (AD), there are several steps to follow in order to configure your service account `AppSvcAccount` securely. These steps ensure that your service account has least privileges necessary to function properly:

  1. Create the Service Account: Firstly, you would create the `AppSvcAccount` in Active Directory. Typically, this would be a user account, but would be labeled or named in a way to identify that it is to be used as a service account.
  2. Use a Strong Password: Assign a strong password to this account. Ensure that the password complexity policy is enforced on this account.
  3. Disable Password Expiry: For service accounts, you might want to consider disabling password expiry. This is because if the password expires, services associated with the account could stop functioning. However, this should be balanced against the security risk of the password being compromised. As an alternative, implement a procedure for regularly updating the service account password, and coordinate this procedure with a restart of the associated service.
  4. Account Options: Make sure the options “User cannot change password” and “Password never expires” are selected. This will prevent the service account’s password from being changed accidentally and causing service disruptions.
  5. Grant Log on as a Service Rights: If the service account is used to run a Windows service, it will need the “Log on as a service” right. You can do this through the Local Security Policy.
  6. Assign Only Required AD Permissions: Grant only the required permissions on specific organizational units (OUs), directories, or other resources that the service account needs to access. Avoid giving the service account broad or administrative permissions.
  7. Managed Service Account: If possible, consider using a Managed Service Account or Group Managed Service Account. These are special types of accounts in Active Directory that are automatically managed by the system. They are designed to run services so they automatically handle password management, simplifying service account management and increasing security.
  8. Service Configuration: After configuring the service account in AD, you need to configure your service to use this account. This will be dependent on the specific service you’re configuring, but typically involves specifying the service account in the service’s configuration and restarting the service.
  9. Regular Audits: Regularly review and audit the permissions of the service account to ensure it only has what it needs and nothing more.

Remember, the goal is to give this account only the permissions that it needs to perform its functions and no more. Less privilege equates to less risk if the account gets compromised.

 

EXAMPLE

The minimum permissions required for a service account to read (SELECT) and write (INSERT, UPDATE, DELETE) to a specific table (`MyTable` in this case) are those specific permissions on that table.

Let’s suppose your service account is ‘AppSvcAccount’ and the table it needs to interact with is ‘MyTable’.

In SQL Server, you would grant the permissions like this:

For SELECT/Read permissions
GRANT SELECT ON dbo.MyTable TO AppSvcAccount;

For INSERT permissions
GRANT INSERT ON dbo.MyTable TO AppSvcAccount;

For UPDATE permissions
GRANT UPDATE ON dbo.MyTable TO AppSvcAccount;

For DELETE permissions
GRANT DELETE ON dbo.MyTable TO AppSvcAccount;

On the Active Directory side, there are no direct permissions related to SQL Server table access. Active Directory controls access to the SQL Server itself.

However, if you’re using Windows Authentication to connect to SQL Server, ‘AppSvcAccount‘ would need to be a valid account in your Active Directory, and it would need permissions to log in to the SQL Server. That’s done typically by making the ‘AppSvcAccount‘ a member of a domain group, and that group is then given access to SQL Server. For example:

  1. Create a new AD group, let’s call it ‘SQLAccessGroup‘.
  2. Add ‘AppSvcAccount‘ to ‘SQLAccessGroup‘.
  3. In SQL Server, create a new login for ‘SQLAccessGroup‘ and grant it the necessary connect permissions.

By limiting the SQL Server permissions to only what’s necessary for ‘AppSvcAccount‘ to perform its tasks (reading and writing to ‘MyTable‘), you’re following the principle of least privilege and enhancing the security of your system.